From: Benjamin LaHaise <bcrl@kvack.org>
In __alloc_skb(), the use of skb_shinfo() which casts a u8 * to the
shared info structure results in gcc being forced to do a reload of the
pointer since it has no information on possible aliasing. Fix this by
using a pointer to refer to skb_shared_info.
By initializing skb_shared_info sequentially, the write combining buffers
can reduce the number of memory transactions to a single write. Reorder
the initialization in __alloc_skb() to match the structure definition.
There is also an alignment issue on 64 bit systems with skb_shared_info
by converting nr_frags to a short everything packs up nicely.
Also, pass the slab cache pointer according to the fclone flag instead
of using two almost identical function calls.
This raises bw_unix performance up to a peak of 707KB/s when combined
with the spinlock patch. It should help other networking protocols, too.
Signed-off-by: David S. Miller <davem@davemloft.net>
sock_init can be done as a core_initcall instead of calling
it directly in init/main.c
Also I removed an out of date #ifdef.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a packet is obtained from skb_recv_datagram with MSG_PEEK enabled
it is left on the socket receive queue. This means that when we detect
a checksum error we have to be careful when trying to free the packet
as someone could have dequeued it in the time being.
Currently this delicate logic is duplicated three times between UDPv4,
UDPv6 and RAWv6. This patch moves them into a one place and simplifies
the code somewhat.
This is based on a suggestion by Eric Dumazet.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Here is the patch that introduces the generic skb_checksum_complete
which also checks for hardware RX checksum faults. If that happens,
it'll call netdev_rx_csum_fault which currently prints out a stack
trace with the device name. In future it can turn off RX checksum.
I've converted every spot under net/ that does RX checksum checks to
use skb_checksum_complete or __skb_checksum_complete with the
exceptions of:
* Those places where checksums are done bit by bit. These will call
netdev_rx_csum_fault directly.
* The following have not been completely checked/converted:
ipmr
ip_vs
netfilter
dccp
This patch is based on patches and suggestions from Stephen Hemminger
and David S. Miller.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The existing connection tracking subsystem in netfilter can only
handle ipv4. There were basically two choices present to add
connection tracking support for ipv6. We could either duplicate all
of the ipv4 connection tracking code into an ipv6 counterpart, or (the
choice taken by these patches) we could design a generic layer that
could handle both ipv4 and ipv6 and thus requiring only one sub-protocol
(TCP, UDP, etc.) connection tracking helper module to be written.
In fact nf_conntrack is capable of working with any layer 3
protocol.
The existing ipv4 specific conntrack code could also not deal
with the pecularities of doing connection tracking on ipv6,
which is also cured here. For example, these issues include:
1) ICMPv6 handling, which is used for neighbour discovery in
ipv6 thus some messages such as these should not participate
in connection tracking since effectively they are like ARP
messages
2) fragmentation must be handled differently in ipv6, because
the simplistic "defrag, connection track and NAT, refrag"
(which the existing ipv4 connection tracking does) approach simply
isn't feasible in ipv6
3) ipv6 extension header parsing must occur at the correct spots
before and after connection tracking decisions, and there were
no provisions for this in the existing connection tracking
design
4) ipv6 has no need for stateful NAT
The ipv4 specific conntrack layer is kept around, until all of
the ipv4 specific conntrack helpers are ported over to nf_conntrack
and it is feature complete. Once that occurs, the old conntrack
stuff will get placed into the feature-removal-schedule and we will
fully kill it off 6 months later.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Change netem to support packets getting reordered because of variations in
delay. Introduce a special case version of FIFO that queues packets in order
based on the netem delay.
Since netem is classful, those users that don't want jitter based reordering
can just insert a pfifo instead of the default.
This required changes to generic skbuff code to allow finer grain manipulation
of sk_buff_head. Insertion into the middle and reverse walk.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Attached is kernel patch for UDP Fragmentation Offload (UFO) feature.
1. This patch incorporate the review comments by Jeff Garzik.
2. Renamed USO as UFO (UDP Fragmentation Offload)
3. udp sendfile support with UFO
This patches uses scatter-gather feature of skb to generate large UDP
datagram. Below is a "how-to" on changes required in network device
driver to use the UFO interface.
UDP Fragmentation Offload (UFO) Interface:
-------------------------------------------
UFO is a feature wherein the Linux kernel network stack will offload the
IP fragmentation functionality of large UDP datagram to hardware. This
will reduce the overhead of stack in fragmenting the large UDP datagram to
MTU sized packets
1) Drivers indicate their capability of UFO using
dev->features |= NETIF_F_UFO | NETIF_F_HW_CSUM | NETIF_F_SG
NETIF_F_HW_CSUM is required for UFO over ipv6.
2) UFO packet will be submitted for transmission using driver xmit routine.
UFO packet will have a non-zero value for
"skb_shinfo(skb)->ufo_size"
skb_shinfo(skb)->ufo_size will indicate the length of data part in each IP
fragment going out of the adapter after IP fragmentation by hardware.
skb->data will contain MAC/IP/UDP header and skb_shinfo(skb)->frags[]
contains the data payload. The skb->ip_summed will be set to CHECKSUM_HW
indicating that hardware has to do checksum calculation. Hardware should
compute the UDP checksum of complete datagram and also ip header checksum of
each fragmented IP packet.
For IPV6 the UFO provides the fragment identification-id in
skb_shinfo(skb)->ip6_frag_id. The adapter should use this ID for generating
IPv6 fragments.
Signed-off-by: Ananda Raju <ananda.raju@neterion.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (forwarded)
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Add kernel-doc to skbuff.h, skbuff.c to eliminate kernel-doc warnings.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
- added typedef unsigned int __nocast gfp_t;
- replaced __nocast uses for gfp flags with gfp_t - it gives exactly
the same warnings as far as sparse is concerned, doesn't change
generated code (from gcc point of view we replaced unsigned int with
typedef) and documents what's going on far better.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I've found the problem in general. It affects any 64-bit
architecture. The problem occurs when you change the system time.
Suppose that when you boot your system clock is forward by a day.
This gets recorded down in skb_tv_base. You then wind the clock back
by a day. From that point onwards the offset will be negative which
essentially overflows the 32-bit variables they're stored in.
In fact, why don't we just store the real time stamp in those 32-bit
variables? After all, we're not going to overflow for quite a while
yet.
When we do overflow, we'll need a better solution of course.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since packets almost never contain extra garbage at the end, it is
worthwhile to optimize for that case.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The new timestamp get/set routines should have const attribute
on parameters (helps to indicate direction).
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Protocols that make extensive use of SKB cloning,
for example TCP, eat at least 2 allocations per
packet sent as a result.
To cut the kmalloc() count in half, we implement
a pre-allocation scheme wherein we allocate
2 sk_buff objects in advance, then use a simple
reference count to free up the memory at the
correct time.
Based upon an initial patch by Thomas Graf and
suggestions from Herbert Xu.
Signed-off-by: David S. Miller <davem@davemloft.net>
Of this type, mostly:
CHECK net/ipv6/netfilter.c
net/ipv6/netfilter.c:96:12: warning: symbol 'ipv6_netfilter_init' was not declared. Should it be static?
net/ipv6/netfilter.c:101:6: warning: symbol 'ipv6_netfilter_fini' was not declared. Should it be static?
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Bonding just wants the device before the skb_bond()
decapsulation occurs, so simply pass that original
device into packet_type->func() as an argument.
It remains to be seen whether we can use this same
exact thing to get rid of skb->input_dev as well.
Signed-off-by: David S. Miller <davem@davemloft.net>
This removes the private element from skbuff, that is only used by
HIPPI. Instead it uses skb->cb[] to hold the additional data that is
needed in the output path from hard_header to device driver.
PS: The only qdisc that might potentially corrupt this cb[] is if
netem was used over HIPPI. I will take care of that by fixing netem
to use skb->stamp. I don't expect many users of netem over HIPPI
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove the "list" member of struct sk_buff, as it is entirely
redundant. All SKB list removal callers know which list the
SKB is on, so storing this in sk_buff does nothing other than
taking up some space.
Two tricky bits were SCTP, which I took care of, and two ATM
drivers which Francois Romieu <romieu@fr.zoreil.com> fixed
up.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
As discussed at netconf'05, we're trying to save every bit in sk_buff.
The patch below makes sk_buff 8 bytes smaller. I did some basic
testing on my notebook and it seems to work.
The only real in-tree user of nfcache was IPVS, who only needs a
single bit. Unfortunately I couldn't find some other free bit in
sk_buff to stuff that bit into, so I introduced a separate field for
them. Maybe the IPVS guys can resolve that to further save space.
Initially I wanted to shrink pkt_type to three bits (PACKET_HOST and
alike are only 6 values defined), but unfortunately the bluetooth code
overloads pkt_type :(
The conntrack-event-api (out-of-tree) uses nfcache, but Rusty just
came up with a way how to do it without any skb fields, so it's safe
to remove it.
- remove all never-implemented 'nfcache' code
- don't have ipvs code abuse 'nfcache' field. currently get's their own
compile-conditional skb->ipvs_property field. IPVS maintainers can
decide to move this bit elswhere, but nfcache needs to die.
- remove skb->nfcache field to save 4 bytes
- move skb->nfctinfo into three unused bits to save further 4 bytes
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
As discussed at netconf'05, we convert nfmark and conntrack-mark to be
32bits even on 64bit architectures.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are many instances of
skb->protocol = htons(ETH_P_*);
skb->protocol = __constant_htons(ETH_P_*);
and
skb->protocol = *_type_trans(...);
Most of *_type_trans() are already endian-annotated, so, let's shift
attention on other warnings.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
From: Victor Fusco <victor@cetuc.puc-rio.br>
Fix the sparse warning "implicit cast to nocast type"
Signed-off-by: Victor Fusco <victor@cetuc.puc-rio.br>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
From: Victor Fusco <victor@cetuc.puc-rio.br>
Fix the sparse warning "implicit cast to nocast type"
Signed-off-by: Victor Fusco <victor@cetuc.puc-rio.br>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reduce local_df to a bit field and ip_summed to a 2 bits
field thus saving 13 bits. Move bit fields, packet type,
and protocol into the spare area between the priority
and the destructor. Saves 4 bytes on both, 32bit and
64bit architectures.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is the code to load packet data into a register:
k = fentry->k;
if (k < 0) {
...
} else {
u32 _tmp, *p;
p = skb_header_pointer(skb, k, 4, &_tmp);
if (p != NULL) {
A = ntohl(*p);
continue;
}
}
skb_header_pointer checks if the requested data is within the
linear area:
int hlen = skb_headlen(skb);
if (offset + len <= hlen)
return skb->data + offset;
When offset is within [INT_MAX-len+1..INT_MAX] the addition will
result in a negative number which is <= hlen.
I couldn't trigger a crash on my AMD64 with 2GB of memory, but a
coworker tried on his x86 machine and it crashed immediately.
This patch fixes the check in skb_header_pointer to handle large
positive offsets similar to skb_copy_bits. Invalid data can still
be accessed using negative offsets (also similar to skb_copy_bits),
anyone using negative offsets needs to verify them himself.
Thanks to Thomas Vgtle <thomas.voegtle@coreworks.de> for verifying the
problem by crashing his machine and providing me with an Oops.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Finds a pattern in the skb data according to the specified
textsearch configuration. Use textsearch_next() to retrieve
subsequent occurrences of the pattern. Returns the offset
to the first occurrence or UINT_MAX if no match was found.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implements sequential reading for both linear and non-linear
skb data at zerocopy cost. The data is returned in chunks of
arbitary length, therefore random access is not possible.
Usage:
from := 0
to := 128
state := undef
data := undef
len := undef
consumed := 0
skb_prepare_seq_read(skb, from, to, &state)
while (len = skb_seq_read(consumed, &data, &state)) != 0 do
/* do something with 'data' of length 'len' */
if abort then
/* abort read if we don't wait for
* skb_seq_read() to return 0 */
skb_abort_seq_read(&state)
return
endif
/* not necessary to consume all of 'len' */
consumed += len
done
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some KernelDoc descriptions are updated to match the current code.
No code changes.
Signed-off-by: Martin Waitz <tali@admingilde.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I have recompiled Linux kernel 2.6.11.5 documentation for me and our
university students again. The documentation could be extended for more
sources which are equipped by structured comments for recent 2.6 kernels. I
have tried to proceed with that task. I have done that more times from 2.6.0
time and it gets boring to do same changes again and again. Linux kernel
compiles after changes for i386 and ARM targets. I have added references to
some more files into kernel-api book, I have added some section names as well.
So please, check that changes do not break something and that categories are
not too much skewed.
I have changed kernel-doc to accept "fastcall" and "asmlinkage" words reserved
by kernel convention. Most of the other changes are modifications in the
comments to make kernel-doc happy, accept some parameters description and do
not bail out on errors. Changed <pid> to @pid in the description, moved some
#ifdef before comments to correct function to comments bindings, etc.
You can see result of the modified documentation build at
http://cmp.felk.cvut.cz/~pisa/linux/lkdb-2.6.11.tar.gz
Some more sources are ready to be included into kernel-doc generated
documentation. Sources has been added into kernel-api for now. Some more
section names added and probably some more chaos introduced as result of quick
cleanup work.
Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: Martin Waitz <tali@admingilde.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Here is a revised alternative that uses BUG_ON/WARN_ON
(as suggested by Herbert Xu) to eliminate NET_CALLER.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
So here is a patch that introduces skb_store_bits -- the opposite of
skb_copy_bits, and uses them to read/write the csum field in rawv6.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Benjamin LaHaise